From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3F331D12D41 for ; Sun, 10 Nov 2024 15:00:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=6yQ2rSFv92DtBGpphymSQaues8rEpqWzpk14XviiUck=; b=g3QMuOZkjGHjSv/W9o/5QKGyGJ oqnK7eVmyRHv++H0uDJo5LCnDUm1JR0oRvzjqNBzIJH3C2HTcSqNMNo99VYHnU5BBem/GHDVkJMpG rlsOVQwqUv2xMAswbayrw0jcFa4rRXWnk1pDxZK+0VnmCQ2lLZzEXja1Dt5waEqjcCv37tuicg1QR mm9Ymdjf3RKfM0k+SznhJdpT56G55dXTeSNCBu/gi777/9edC93tYkTAACI2GGRySqyvd51PMOjQz owRmpHBK44gtRqbHGwiL0rxdh895rYbMLQhEcmkXT00T4nrjFbYhKs+2QBM+YiQfwuTdj7JNPP/Z4 xMFzOjfQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tA9QF-0000000F4Gh-1aEU; Sun, 10 Nov 2024 15:00:15 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tA8IO-0000000Ewxc-3oHm for linux-nvme@lists.infradead.org; Sun, 10 Nov 2024 13:48:15 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id AA7655C55E8; Sun, 10 Nov 2024 13:47:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A209CC4CED6; Sun, 10 Nov 2024 13:48:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1731246483; bh=GYKFLxFW0CYXNWuiPU0aCZhm6hh5vt2InRoRMGBEU+M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qqtVQlI3fq4sD3SKnuEz04hLzE6U1ARAVw/NCQh67prYU64s/47IpjY6HTDT0/2Z2 YksKCuzOzVJa+mwHYQJGPPBE8cpdo7leAlIchAI7A3R2gj2KVcKvysgQ0LRfLP9BqG e+DDu/Yd4UtZ9hhtA2+UJg5zCneD8UhuthY96oNMqtQrSL+A2BWkTMU8ECAL99I1j1 HsUpnH+Liy3uvyljvqDo6RnVXckDfumweHcbHLmtDK+BsazYmoYb59KKK+DYhnqzga vCFFeKw/HJhnsC/UZom+tkagbhJPy9DmDe9fOoiuyPoDwiznUJ0w+Z4qvjtYsIvB5P etOuel8UK4xIg== From: Leon Romanovsky To: Jens Axboe , Jason Gunthorpe , Robin Murphy , Joerg Roedel , Will Deacon , Christoph Hellwig , Sagi Grimberg Cc: Leon Romanovsky , Keith Busch , Bjorn Helgaas , Logan Gunthorpe , Yishai Hadas , Shameer Kolothum , Kevin Tian , Alex Williamson , Marek Szyprowski , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Andrew Morton , Jonathan Corbet , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-rdma@vger.kernel.org, iommu@lists.linux.dev, linux-nvme@lists.infradead.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, Randy Dunlap Subject: [PATCH v3 10/17] mm/hmm: let users to tag specific PFN with DMA mapped bit Date: Sun, 10 Nov 2024 15:46:57 +0200 Message-ID: X-Mailer: git-send-email 2.47.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241110_054805_441895_ACB4B6B2 X-CRM114-Status: GOOD ( 19.22 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org From: Leon Romanovsky Introduce new sticky flag (HMM_PFN_DMA_MAPPED), which isn't overwritten by HMM range fault. Such flag allows users to tag specific PFNs with information if this specific PFN was already DMA mapped. Signed-off-by: Leon Romanovsky --- include/linux/hmm.h | 17 +++++++++++++++++ mm/hmm.c | 39 ++++++++++++++++++++++++++------------- 2 files changed, 43 insertions(+), 13 deletions(-) diff --git a/include/linux/hmm.h b/include/linux/hmm.h index 126a36571667..a1ddbedc19c0 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -23,6 +23,8 @@ struct mmu_interval_notifier; * HMM_PFN_WRITE - if the page memory can be written to (requires HMM_PFN_VALID) * HMM_PFN_ERROR - accessing the pfn is impossible and the device should * fail. ie poisoned memory, special pages, no vma, etc + * HMM_PFN_DMA_MAPPED - Flag preserved on input-to-output transformation + * to mark that page is already DMA mapped * * On input: * 0 - Return the current state of the page, do not fault it. @@ -36,6 +38,13 @@ enum hmm_pfn_flags { HMM_PFN_VALID = 1UL << (BITS_PER_LONG - 1), HMM_PFN_WRITE = 1UL << (BITS_PER_LONG - 2), HMM_PFN_ERROR = 1UL << (BITS_PER_LONG - 3), + + /* + * Sticky flags, carried from input to output, + * don't forget to update HMM_PFN_INOUT_FLAGS + */ + HMM_PFN_DMA_MAPPED = 1UL << (BITS_PER_LONG - 7), + HMM_PFN_ORDER_SHIFT = (BITS_PER_LONG - 8), /* Input flags */ @@ -57,6 +66,14 @@ static inline struct page *hmm_pfn_to_page(unsigned long hmm_pfn) return pfn_to_page(hmm_pfn & ~HMM_PFN_FLAGS); } +/* + * hmm_pfn_to_phys() - return physical address pointed to by a device entry + */ +static inline phys_addr_t hmm_pfn_to_phys(unsigned long hmm_pfn) +{ + return __pfn_to_phys(hmm_pfn & ~HMM_PFN_FLAGS); +} + /* * hmm_pfn_to_map_order() - return the CPU mapping size order * diff --git a/mm/hmm.c b/mm/hmm.c index 7e0229ae4a5a..c16cfa03430c 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -39,13 +39,20 @@ enum { HMM_NEED_ALL_BITS = HMM_NEED_FAULT | HMM_NEED_WRITE_FAULT, }; +enum { + /* These flags are carried from input-to-output */ + HMM_PFN_INOUT_FLAGS = HMM_PFN_DMA_MAPPED, +}; + static int hmm_pfns_fill(unsigned long addr, unsigned long end, struct hmm_range *range, unsigned long cpu_flags) { unsigned long i = (addr - range->start) >> PAGE_SHIFT; - for (; addr < end; addr += PAGE_SIZE, i++) - range->hmm_pfns[i] = cpu_flags; + for (; addr < end; addr += PAGE_SIZE, i++) { + range->hmm_pfns[i] &= HMM_PFN_INOUT_FLAGS; + range->hmm_pfns[i] |= cpu_flags; + } return 0; } @@ -202,8 +209,10 @@ static int hmm_vma_handle_pmd(struct mm_walk *walk, unsigned long addr, return hmm_vma_fault(addr, end, required_fault, walk); pfn = pmd_pfn(pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); - for (i = 0; addr < end; addr += PAGE_SIZE, i++, pfn++) - hmm_pfns[i] = pfn | cpu_flags; + for (i = 0; addr < end; addr += PAGE_SIZE, i++, pfn++) { + hmm_pfns[i] &= HMM_PFN_INOUT_FLAGS; + hmm_pfns[i] |= pfn | cpu_flags; + } return 0; } #else /* CONFIG_TRANSPARENT_HUGEPAGE */ @@ -236,7 +245,7 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, hmm_pte_need_fault(hmm_vma_walk, pfn_req_flags, 0); if (required_fault) goto fault; - *hmm_pfn = 0; + *hmm_pfn = *hmm_pfn & HMM_PFN_INOUT_FLAGS; return 0; } @@ -253,14 +262,14 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, cpu_flags = HMM_PFN_VALID; if (is_writable_device_private_entry(entry)) cpu_flags |= HMM_PFN_WRITE; - *hmm_pfn = swp_offset_pfn(entry) | cpu_flags; + *hmm_pfn = (*hmm_pfn & HMM_PFN_INOUT_FLAGS) | swp_offset_pfn(entry) | cpu_flags; return 0; } required_fault = hmm_pte_need_fault(hmm_vma_walk, pfn_req_flags, 0); if (!required_fault) { - *hmm_pfn = 0; + *hmm_pfn = *hmm_pfn & HMM_PFN_INOUT_FLAGS; return 0; } @@ -304,11 +313,11 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, pte_unmap(ptep); return -EFAULT; } - *hmm_pfn = HMM_PFN_ERROR; + *hmm_pfn = (*hmm_pfn & HMM_PFN_INOUT_FLAGS) | HMM_PFN_ERROR; return 0; } - *hmm_pfn = pte_pfn(pte) | cpu_flags; + *hmm_pfn = (*hmm_pfn & HMM_PFN_INOUT_FLAGS) | pte_pfn(pte) | cpu_flags; return 0; fault: @@ -448,8 +457,10 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end, } pfn = pud_pfn(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); - for (i = 0; i < npages; ++i, ++pfn) - hmm_pfns[i] = pfn | cpu_flags; + for (i = 0; i < npages; ++i, ++pfn) { + hmm_pfns[i] &= HMM_PFN_INOUT_FLAGS; + hmm_pfns[i] |= pfn | cpu_flags; + } goto out_unlock; } @@ -507,8 +518,10 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask, } pfn = pte_pfn(entry) + ((start & ~hmask) >> PAGE_SHIFT); - for (; addr < end; addr += PAGE_SIZE, i++, pfn++) - range->hmm_pfns[i] = pfn | cpu_flags; + for (; addr < end; addr += PAGE_SIZE, i++, pfn++) { + range->hmm_pfns[i] &= HMM_PFN_INOUT_FLAGS; + range->hmm_pfns[i] |= pfn | cpu_flags; + } spin_unlock(ptl); return 0; -- 2.47.0